获取与Python的for循环中的另一个列表的项目匹配的列表的项目

Question

I'm really new to Python so first of all sorry if I'm asking something too obvious... I have a list of strings like:

a = ['car/red/1','car/red/2','bike/red/1','bike/red/3','skate/blue/1','skate/blue/2']

And another list with substrings like:

b = ['car/red','bike/red','skate/blue']

How can I iterate list "a" extracting everytime the matches of an item in b? I want something like:

for i in b: matches = [x for x in a if i in x] print matches

So the first pass of this would print 'car/red/1' and 'card/red/2', the second would print 'bike/red/1' and 'bike/red/3' and the third would print 'skate/blue/1' and 'skate/blue/2'.

Answer 1

for item in b:
    print [x for x in a if item in x]

The above will return

['car/red/1', 'car/red/2']
['bike/red/1', 'bike/red/3']
['skate/blue/1', 'skate/blue/2']

We are traversing each b_item in b and then using list comprehension to print a new array of any a_item from a of which b_item is a substring

Answer 2

Not sure if this would help. I know there must be more precise approach. But give the following code a try

a = ['car/red/1','car/red/2','bike/red/1','bike/red/3','skate/blue/1','skate/blue/2']

b = ['car/red','bike/red','skate/blue']

for i in a:
    for j in b:
        if i in j:
            print j

Answer 3

Based on your expectation, I might want to use startwith.

a = ['car/red/1','car/red/2','bike/red/1','bike/red/3','skate/blue/1','skate/blue/2']
b = ['car/red','bike/red','skate/blue']

for ii in b:
    matches = [x for x in a if x.startswith(ii)]
    print(matches)

Result is the following:

['car/red/1', 'car/red/2']
['bike/red/1', 'bike/red/3']
['skate/blue/1', 'skate/blue/2']